John Goss was fired after he was interviewed for an episode of Dispatches that claimed the low-cost airline’s pilots are wary of raising concerns.

As well as planning to sue Channel 4 over the programme, Ryanair said on Thursday it “will not allow an... employee to defame our safety on national television just three weeks after he confirmed in writing to Ryanair that he had no concerns with safety”.

The airline claimed Mr Goss had confirmed in writing on July 10 and August 13 that he had “no concerns” about the Dublin-based carrier’s safety.

Mr Goss will not comment on his dismissal until he receives further legal advice, said a spokesman for the Ryanair Pilot Group (RPG), which is advising him.

He has been involved in legal disputes with Ryanair management in the past over issues related to union representation for pilots.

Dispatches, which aired on Monday, claimed that an RPG survey found more than 1,000 pilots, a third of the total, had deep misgivings over the airline’s approach to their concerns.

Ryanair has disputed the legitimacy of RPG and the survey.

The survey was triggered by a memorandum to pilots by management following an earlier petition. Ryanair warned that any pilot signing what it described as a “so-called safety petition” could be sacked for gross misconduct.

More than nine out of 10 pilots who participated in the survey said they believed the airline was trying to suppress pilots from raising their concerns.

The IAA said all confidential reports are fully investigated and its oversight of Ryanair was comprehensive. Ryanair said it has two confidential reporting systems in place, and insisted the IAA had “no concerns over Ryanair’s fuel policy”.

The company has declined to comment on the claims, describing RPG as a “PR front for the pilot unions of competitor airlines”.